Copper-zinc-lead-phosphorous alloy and articles



' Patented 1,1936

UNITED STATES oorrna-zmo-nnan-rnosrnonous annoy AND .m'rrcms Harold L.Pierson, Torrington, Conn., assignor to The American Brass Company,Waterbury, Conn, a corporation of. Connecticut No Drawing. ApplicationAugust 26, 1936,

Serial No. 98,063

8 Claims. (01. 75-155) This invention relates to a leaded copper-zincalloy having improved strength and other properties, and also to amachined article made of this alloy, and particularly to an improvedhigh copper leaded alloy for screw machine work.

A particular object of the invention is to produce a readily'machinablealloy which has a high strength, is tougher and has increased resistanceto abuse, and which resists deformation under ac- 10 tion of a wrench,that is has increased resistance to distortion. It has been known to addlead to copper-zinc alloys to improve their machining or cuttingproperties. It has also been known to add small amounts of phosphorus tocopper-zinc alloys as a deoxidizer.

I have found that by adding a relatively large amount of phosphorus,about 0.25%, to leaded copper-zinc alloys an increase of from 10 to a;in tensile strength is secured, and this is accomplished without anylowering of the elongation. The phosphorizing of the alloy also improvesits extrusion properties. It can be more easily extruded and with lesspressure.

g5 It also tends to make sounder castings and the alloy can be cast at alower pouring temperature.

In this alloy the range of copper may be from about 67% to about 91%,the lead from about 0.35% to about 4%, the phosphorus from about 0.15%to about 0.5%, and the balance zinc. I have found that at about 0.15%phosphorus and up to about 0.5% there is'a material increase in tensilestrength, there being a marked increase at about 0.15% and with thegreatest eifect at about 0.25% phosphorus. There is only a very.

composed of about 90% copper, about 1.75%

lead, about 0.15% to 0.5% phosphorus and balance zinc.-

.Another very useful alloy is composed of about 85% copper, 1.75% lead,0.15% to 0.5% phosphorus and balance zinc. The above alloy has beenfound to be tougher with high strength, andas having greater resistanceto distortion and abuse, such for example as deformation under action ofa wrench, than the same aHoy without the phosphorus. It is tough andstill is ductile.- It has'been found to i be very useful and a greatimprovement for 5 splicing clamps and similar accessories for theelectrical industry. Heretofore considerable trouble has been met insuch devices in the strip-.- ping of threads and pulling ofl of. theheads of bolts .when they were set up tight with a wrench. 10 a Thistrouble is greatly reduced with this improved alloy. r

It is also of course adapted for many other uses where these improvedproperties are desirable.

vThe alloy has good corrosion resistance being 15 f equal to or betterthan copper (depending upon the corrosive agent and the method of itsuse) and may obviously be used to advantage wherever corrosion resistantproperties are desired, with the added advantages of strength,hardnessand 20 wear resistance superior-to copper. I

Having thus set forth the nature of my invention, what Iclaim is:

1. A copper base alloy composed of about 67% to 91% copper, 0.35% to4%lead, 0.15am 0.5% as copper, 1.75% lead, 0.15% to 0.5% phosphorus, I

and balancezinc.

- 4. A copper basealloy composed of about 85%,

copper, 1.75% lead; 0.15% to 0.5% phosphorus, andbalance zinc. V

5. A machined article made from an alloy composed of about 67%to 91%copper, 0.35% to 4% lead, 0.15% to 0.5% phosphorus, and balance zinc. a

6. A machined article made from an alloy com- 40 posed of about to 90%copper,.0.35% to 4% 5 lead, 0.15% to 0.5% phosphorus, and balanc zinc. x

7. A machined article made from an alloy composed-ofabout 90% copper,1.75% lead, 0.15% to $5 0.5% phosphorus and balance 'zinc. I

8. A machined article made from an alloy com-' posed of about copper,1.75% lead, 0.15% to 0.5% phosphorus, and balance zinc.

mom 1.. Pnmson.

